Use of vinyl chloride-ethylene copolymers for hydrophobing construction substances

ABSTRACT

Copolymers of ethylene and vinyl chloride also containing a protective colloid, optionally in conjunction with a fatty acid compound or precursor thereof or with an organosilicon compound, can be employed to increase the water repellancy of hydraulically settable construction materials.

The invention relates to the use of vinyl chloride-ethylene copolymersfor imparting water repellency to construction materials, especially forsurface-coating materials such as skim coats, monocouche coatings andjoint fillers.

Polymers based on vinyl ester, vinyl chloride, (meth)acrylate monomers,styrene, butadiene and ethylene are employed in particular in the formof their aqueous dispersions or water-redispersible polymer powders innumerous applications, for example as coating materials or adhesives forany of a very wide variety of substrates. These polymers are stabilizedusing protective colloids or surface-active compounds of low molecularmass. Protective colloids used are generally polyvinyl alcohols. Theseproducts find use in particular as binders in hydraulically settingadhesives such as tile adhesives, for example, or in plasters orlevelling compounds based on cements or gypsums.

Skim coats or monocouche and joint fillers are each applications whichimpose very exacting requirements on the water resistance or waterrepellency of the finished components. By skim coats are meant very thinfinish-coat plasters or smoothing-trowel applications with a thicknessof generally 1 to 2 mm. Monocouche is a term for single-coat plasterswhich at the same time are decorative plasters. In order to meet thewater repellency requirements of these applications, the formulationsmust be hydrophobically modified accordingly.

From DE-A 2341085, EP-A 342609, EP-A 717016 and EP-A 1193287 it is knownto add fatty acid esters as water repellents to lime- or cement-boundplasters. A disadvantage in this case is often the actual hydrophobizingnature of these additives. When dry plasters which include such waterrepellents are stirred into water, the materials are wetted only poorly,and therefore the processing properties are markedly impaired.

Water-redispersible powders based on homopolymers or copolymers ofethylenically unsaturated monomers are used in the building sector asbinders, in combination with hydraulically setting binders such ascement. In building adhesives, plasters, mortars and paints, forexample, they serve to improve the mechanical strength and the adhesion.From WO-A 95/20627, WO-A 02/31036 and DE-A 10233933 it is known to usehydrophobizing additives such as organosilicon compounds and fatty acidesters as a component of redispersible powders in dry mortars. Thiscircumvents the problem of the poor wettability and processingproperties. The hydrophobicizing effect, however, is dependent on theproportion of the water repellent in the redispersible powder, andtherefore cannot be varied arbitrarily.

From EP-A 149098 and EP-A 224169 it is known to use vinylchloride-ethylene copolymers as an additive to hydraulically settingcompositions for the purpose of improving their mechanical strength,especially compressive strength, abrasion resistance, flexural strengthunder tension and adhesive strength under tension.

An object which existed was to provide a polymer composition in the formof its aqueous dispersion or in the form of its water-redispersiblepowder which is suitable for use in construction materials for which avery high water repellency effect is required. For joint fillers,modified with 1% by weight of polymer, based on dry mass, the waterabsorption according to EN 12808 after 3 hours should be ≦5 ml. Forskim-coat plasters, modified with 1% by weight of polymer, based on drymass, the water absorption determined by the method of Karsten is to be≦2 ml after 300 minutes.

The invention provides for the use of polymer compositions in the formof their aqueous dispersion or in the form of their water-redispersiblepowder for imparting water repellency to construction materials,comprising

a) a vinyl chloride-ethylene copolymer and

b) 5% to 30% by weight of one or more protective colloids, and also

c) in powder form, 5% to 30% by weight of one or more anti-blockingagents, and also,

if desired, further additives,

the amounts in % by weight being based on the total weight of thepolymer powder composition and adding up in each case to 100% by weight.

The vinyl chloride-ethylene copolymer contains preferably 50% to 95% byweight of vinyl chloride units, 5% to 30% by weight of ethylene units,more preferably 75% to 90% by weight of vinyl chloride units, 10% to 25%by weight of ethylene units, based in each case on the total weight ofthe copolymer.

If desired it is also possible for up to 20% by weight of furthercomonomers to have been copolymerized. Examples thereof are monomersfrom the group consisting of vinyl esters, (meth)acrylic esters andvinylaromatics. Suitable vinyl esters are those of carboxylic acidshaving 1 to 12 carbon atoms. Preference is given to vinyl acetate,1-methylvinyl acetate, vinyl esters of α-branched monocarboxylic acidshaving 9 to 11 carbon atoms, examples being VeoVa9^(R) or VeoVa10^(R)(trade names of the company Resolution). Suitable monomers from theacrylic and methacrylic ester group are esters with branched orunbranched alcohols having 1 to 15 carbon atoms. Preferred acrylic andmethacrylic esters are methyl acrylate, methyl methacrylate, n-butylacrylate, t-butyl acrylate and 2-ethyl-hexyl acrylate. A preferredvinylaromatic is styrene.

If desired it is also possible for 0.1% to 5% by weight, based on thetotal weight of the monomer mixture, of auxiliary monomers to becopolymerized. Preference is given to ethylenically unsaturatedmonocarboxylic and dicarboxylic acids such as acrylic acid andmethacrylic acid; ethylenically unsaturated carboxamides andcarbonitriles such as acrylamide and acrylonitrile; and ethylenicallyunsaturated sulphonic acids and their salts, preferably vinylsulphonicacid or 2-acrylamido-2-methylpropanesulphonic acid. Further examples arepre-crosslinking comonomers such as polyethylenically unsaturatedcomonomers, examples being divinyl adipate, diallyl maleate, allylmethacrylate and triallyl cyanurate, or post-crosslinking comonomers,examples being N-methylolacrylamide (NMA), alkyl ethers such as theisobutoxy ether or esters of N-methylolacrylamide. Further examples aresilicon-functional comonomers, such as(meth)acryloyloxypropyltri(alkoxy)silanes.

The most preferred are vinyl chloride-ethylene copolymers withoutfurther comonomer units.

Suitable protective colloids are water-soluble polymers from the groupconsisting of fully and partly hydrolysed polyvinyl alcohols;polyvinylpyrrolidones; polyvinyl acetals; polysaccharides inwater-soluble form such as starches (amylose and amylopectin),celluloses and their carboxymethyl, methyl, hydroxyethyl andhydroxypropyl derivatives; proteins such as casein and caseinate, soyaprotein, and gelatin; ligno-sulphonates; synthetic polymers such aspoly(meth)acrylic acid, copolymers of (meth)acrylates withcarboxy-functional comonomer units, poly(meth)acrylamide,polyvinylsulphonic acids and the water-soluble copolymers thereof;melamine-formaldehyde sulphonates, naphthalene-formaldehyde sulphonates,styrene-maleic acid copolymers and vinyl ether-maleic acid copolymers.

Preference is given to fully or partly hydrolysed polyvinyl alcoholshaving a degree of hydrolysis of 80 to 100 mol %, especially partiallyhydrolysed polyvinyl alcohols having a degree of hydrolysis of 80 to 95mol % and a Höppler viscosity, in 4% strength aqueous solution, of 1 to30 mPas, preferably 3 to 15 mPas (method according to Höppler at 20° C.,DIN 53015).

Preference is also given to partially or fully hydrolysed,hydrophobically modified polyvinyl alcohols having a degree ofhydrolysis of 80 to 100 mol % and a Höppler viscosity, in 4% strengthaqueous solution, of 1 to 30 mPas, preferably 3 to 15 mPas. Examples ofsuch are partially hydrolysed copolymers of vinyl acetate withhydrophobic comonomers such as isopropenyl acetate, vinyl pivalate,vinyl ethylhexanoate, vinyl esters of saturated alpha-branchedmonocarboxylic acids having 5 or 9 to 11 carbon atoms, dialkyl maleatesand dialkyl fumarates such as diisopropyl maleate and diisopropylfumarate, vinyl chloride, vinyl alkyl ethers such as vinyl butyl ether,and alpha-olefins having 2 to 12 carbon atoms such as ethene, propeneand decene. The fraction of the hydrophobic units is preferably 0.1% to10% by weight, based on the total weight of the partially or fullyhydrolysed polyvinyl alcohol. Particular preference is given topartially or fully hydrolysed copolymers of vinyl acetate withisopropenyl acetate, having a degree of hydrolysis of 95 to 100 mol %.Mixtures of the said polyvinyl alcohols can also be used.

Maximum preference is given to partially hydrolysed polyvinyl alcoholshaving a degree of hydrolysis of 85 to 94 mol % and a Höppler viscosity,in 4% strength aqueous solution, of 3 to 15 mPas (Höppler method at 20°C., DIN 53015) and to partially or fully hydrolysed copolymers of vinylacetate with isopropenyl acetate, having a degree of hydrolysis of 95 to100 mol %. The said polyvinyl alcohols are obtainable by means ofprocesses that are known to the skilled person.

Suitable anti-blocking agents c) are Ca carbonate, Mg carbonate, talc,gypsum, ground clays, kaolins such as metakaolin and finely groundaluminium silicates, kieselguhr, colloidal silica gel, and pyrogenicsilicon dioxide, in each case with particle sizes preferably in therange from 10 nm to 10 μm.

Further additives, which can be used optionally, are preferablyhydrophobicizing additives d). Examples of such are additives d1), i.e.,fatty acids and fatty acid derivatives which under alkaline conditionsliberate fatty acid or the corresponding fatty acid anion, and/oradditives d2), i.e., organosilicon compounds. In general, component d)is used in an amount of 1% to 20% by weight, preferably 1% to 10% byweight, based in each case on the total weight of the polymercomposition.

Suitable for use as component d1) are, generally, fatty acids and fattyacid derivatives which under alkaline conditions, preferably a pH>8,liberate fatty acid and/or the corresponding fatty acid anion.Preference is given to fatty acid compounds from the group consisting offatty acids having 8 to 22 carbon atoms, their metal soaps, theiramides, and their esters with monohydric alcohols having 1 to 14 carbonatoms, with glycol, with polyglycol, with polyalkylene glycol, withglycerol, with mono-, di- or triethanolamine, or with monosaccharides.

Suitable fatty acids are branched and unbranched, saturated andunsaturated fatty acids having in each case 8 to 22 carbon atoms.Examples are lauric acid (n-dodecanoic acid), myristic acid(n-tetradecanoic acid), palmitic acid (n-hexadecanoic acid), stearicacid (n-octadecanoic acid) and oleic acid (9-dodecenoic acid).

Suitable methal soaps are those of the abovementioned fatty acids withmetals from main groups 1 to 3 and transition group 2 of the PTE, andalso with ammonium compounds NX₄ ⁺, where X is identical or differentand stands for H, C₁ to C₈ alkyl radical and C₁ to C₈ hydroxyalkylradical. Preference is given to metal soaps with lithium, sodium,potassium, magnesium, calcium, aluminium and zinc and with the ammoniumcompounds.

Suitable fatty acid amides are those obtainable with mono- ordiethanolamine and with the abovementioned C₈ to C₂₂ fatty acids.

Fatty acid esters suitable as component d1) are the C₁ to C₁₄ alkyl andalkylaryl esters of the stated C₈ to C₂₂ fatty acids, preferably methyl,ethyl, propyl, butyl and ethylhexyl esters and also the benzyl esters.

Suitable fatty acid esters are also the mono-, di- and polyglycol estersof the C₈ to C₂₂ fatty acids. Further suitable fatty acid esters are themonoesters and diesters of polyglycols and/or polyalkylene glycolshaving up to 20 oxyalkylene units, such as polyethylene glycol andpolypropylene glycol.

Also suitable are the mono-, di- and tri-fatty acid esters of glycerolwith the stated C₈ to C₂₂ fatty acids, and also the mono-, di- andtri-fatty acid esters of mono-, di- and triethanolamine with the statedC₈ to C₂₂ fatty acids. Also suitable are the fatty acid esters ofsorbitol and mannitol.

Particularly preferred are the C₁ to C₁₄ alkyl and alkylaryl esters oflauric acid and oleic acid, mono- and diglycol esters of lauric acid andoleic acid, and the mono-, di- and tri-fatty acid esters of glycerolwith lauric acid and oleic acid.

Suitable components d2) are silicic esters Si(OR′)₄, silanes such astetraorganosilanes SiR₄ and organoorganoxysilanes SiR_(n)(OR′)_(4-n)with n=1 to 3, polysilanes with preferably the general formulaR₃Si(SiR₂)_(n)SiR₃ with n=0 to 500, organosilanols SiR_(n)(OH)_(4-n),di-, oligo- and polysiloxanes composed of units of the general formulaR_(c)H_(d)Si(OR′)_(e)(OH)_(f)O_((4-c-d-e-f)/2) with c=0 to 3, d=0 to 1,e=0 to 3, f=0 to 3 and the sum c+d+e+f not more than 3.5 per unit, R ineach case being identical or different and denoting branched orunbranched alkyl radicals having 1 to 22 carbon atoms, cycloalkylradicals having 3 to 10 carbon atoms, alkylene radicals having 2 to 4carbon atoms, and aryl, aralkyl and alkylaryl radicals having 6 to 18carbon atoms, and R′ denoting identical or different alkyl radicals andalkoxyalkylene radicals having in each case 1 to 4 carbon atoms,preferably methyl and ethyl, it also being possible for the radicals Rand R′ to be substituted by halogens such as Cl or by ether, thioether,ester, amide, nitrile, hydroxyl, amine, carboxyl, sulphonic acid,carboxylic anhydride and carbonyl groups, and in the case of thepolysilanes it also being possible for R to have the definition OR′.Also suitable are carbosilanes, polycarbosilanes, carbosiloxanes,polycarbosiloxanes and polysilylenedisiloxanes.

Preferred components d2) are tetramethoxysilane, tetraethoxy-silane,methyltripropoxysilane, methyltri(ethoxyethoxy)silane,vinyltri(methoxyethoxy)silane, (meth)acryloyloxypropyltri-methoxysilane,(meth)acryloyloxypropyltriethoxysilane, γ-chloropropyltriethoxysilane,β-nitriloethyltriethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-mercaptopropyltriethoxy-silane, phenyltriethoxysilane,isooctyltriethoxysilane, n-octyltriethoxysilane,hexadecyltriethoxysilane, dipropyl-diethoxysilane,methylphenyldiethoxysilane, diphenyldimethoxy-silane,methylvinyltri(ethoxyethoxy)silane, tetramethyl-diethoxydisilane,trimethyltrimethoxydisilane, trimethyl-triethoxydisilane,dimethyltetramethoxydisilane, dimethyltetra-ethoxydisilane,methylhydropolysiloxanes terminally blocked with trimethylsiloxy groups,copolymers of dimethylsiloxane and methylhydrosiloxane units that areterminally blocked with trimethylsiloxy groups, dimethylpolysiloxanes,and also dimethylpolysiloxanes having Si—OH groups in the terminalunits. Maximum preference is given to the organoorganoxysilanesSiR_(n)(OR′)_(4-n) with n=1 to 3, especially isooctyltriethoxy-silane,n-octyltriethoxysilane and hexadecyltriethoxysilane.

The polymer composition is prepared in conventional manner by means offree-radically initiated emulsion polymerization in an aqueous medium,followed by spray drying of the resultant aqueous polymer dispersion.One suitable process, for example, is that described in EP-A 149098. Theemulsion polymerization is carried out in the presence of protectivecolloid and/or emulsifier. Stabilization is preferably effectedexclusively with protective colloid.

The aqueous polymer dispersions thus obtainable generally have a solidscontent of 25% to 70% by weight, preferably 45% to 65% by weight.

To prepare water-redispersible polymer powders the aqueous dispersionsare dried, by means of spray drying for example. Spray drying generallytakes place following the addition of further protective colloid as aspraying aid. The anti-blocking agent c) is preferably added while thepowder is still in suspension in the drying gas. If the powder comprisesfurther additives d), they are added before, during or after spraydrying. Preferably the addition of the additives d) takes place to thepolymer dispersion, prior to the spray drying thereof in the case ofredispersible powders.

The polymer compositions based on vinyl chloride-ethylene copolymers aresuitable for imparting water repellency to hydraulically settingbuilding materials. This is preferably the case in applications whichrequire a very high level of water repellency.

Such applications are, in particular, single-layer coatings (plasters),such as skim coats or monocouche coats, but also joint fillers. By skimcoats are meant very thin finish-coat plasters orsmoothing-trowel-applied systems with a thickness of generally 1 to 3mm. Monocouche is a term for single-coat plasters which at the same timeare decorative plasters. In the case of joint fillers the waterabsorption according to EN 12808 after 3 hours is ≦5 ml. In the case ofplaster coatings the water absorption, determined by the method ofKarsten, should be ≦2 ml after 300 minutes, in each case in formulationscontaining 1% by weight of polymer based on dry mass of the formulation.

Typical formulations for dry mortars are known to the skilled person.They contain 5% to 50% by weight of mineral binder, 5% to 80% by weightof filler, 0.1% to 10% by weight of polymer, and 0% to 30% by weight offurther additives, the amounts in % by weight in the formulation addingup to 100% by weight. Suitable mineral binders are cement, gypsum,waterglass or lime hydrate. Examples of fillers which can be used arecarbonates such as calcium carbonate in the form of dolomite, calciteand chalk. Further examples are silicates, such as magnesium silicate inthe form of talc, or aluminium silicates such as loam and clays; quartzflour, quartz sand, highly disperse silica, feldspar, heavy spar andlight spar. Also suitable are fibrous fillers. In practice, mixtures ofdifferent fillers are frequently used.

Examples of further additives are pigments, an example being titaniumdioxide as an inorganic pigment, and also the customary organicpigments. Examples of further additives are wetting agents in fractionsof generally 0.1% to 0.5% by weight, based on the total weight of theformulation. Examples of such are sodium and potassium polyphosphates,polyacrylic acids and salts thereof. Other additives which may bementioned include thickeners, which are generally used in an amount of0.01% to 2.0% by weight, based on the total weight of the formulation.Customary thickeners are cellulose ethers, starches, or bentonite, as anexample of an inorganic thickener. Further additives are preservatives,defoamers, air-pore formers, plasticizers, retardants, accelerants andfrost preventatives.

To produce the ready-to-use construction materials the dry mortarmodified with the redispersible powder is stirred together with therequired amount of water on the construction site. Dry mortars can alsobe modified on site by adding the aqueous polymer dispersions, dilutedwhere appropriate.

The examples which follow serve to illustrate the invention further.

Dispersion:

The dispersion used was an aqueous, polyvinyl alcohol-stabilizeddispersion of a copolymer of vinyl chloride and ethylene. It wasprepared by emulsion polymerization. It was stabilized using 10% byweight of a polyvinyl alcohol having a degree of hydrolysis of 88 mol %and a Höppler viscosity of 4 mPas. The copolymer composition was 80% byweight vinyl chloride and 20% by weight ethylene.

As a further component the dispersion contained 0% (dispersion 1), 5%(dispersion 2) or 10% (dispersion 3) by weight of methyl dodecanoate(dodecanoic acid methyl ester; DME), based on dry weight.

Powders:

The powders were prepared by spray drying the aforementioneddispersions, in the presence of 10% by weight in each case of apolyvinyl alcohol having a degree of hydrolysis of 88 mol % and aHöppler viscosity of 13 mPas. In the examples indicated in table 1,isooctyltriethoxysilane (IOTS) and, where appropriate, methyldodecanoate (DME) were included at the spray-drying stage. Thedispersion was sprayed by means of a two-fluid nozzle. Precompressed airat 4 bar was used as a spraying component, and the drops formed weredried with heated air at 125° C. in co-current. The dry powder obtainedwas admixed with 10% by weight of standard commercial anti-blockingagent (mixture of calcium magnesium carbonate and magnesiumhydrosilicate).

EXAMPLE 8

Redispersible powder based on a vinyl chloride/vinyl acetate/ethylenecopolymer with a Tg of about 10° C., plus isooctyltriethoxysilane aswater repellency additive.

Comparative Example C1

Redispersible powder based on a vinyl acetate/VeoVa10/butyl acrylatecopolymer with a Tg of about 15° C., plus methyl dodecanoate as waterrepellency additive. TABLE 1 Example Dispersion DME (% by wt.) IOTS (%by wt.) 1 1 0 4 2 1 2 4 3 2 0 4 4 2 2 4 5 3 0 4 6 3 2 4 7 1 0 0 8 4 C1 2

Testing of a Skim Coat Formulation:

Formulation 1 (Skim Coat): Forumlation 1 (skim coat): Portland cement42.5 300.0 parts by weight Calcium carbonate 700.0 parts by weightCellulose ether 2.5 parts by weight Redispersible powder 10.0 parts byweight Total 1012.5 parts by weight Water required 38.0 parts by weight

Determination of Water Absorption by the Karsten Method:

In this test the water absorption, WA, of the specimen was measured, inml, after defined periods of time (in minutes). This was done by using asuitable bonding agent to bond a Karsten glass tube to the testsubstrate as described in DIN EN 1323. After the water tube had beenfilled, the amount of water by the substrate is determined at definedintervals of time. The greater the amount, the poorer the waterrepellency impart to the specimen.

Testing of the Adhesive Strength Under Tension:

To determine the substrate adhesion the mortar was applied to a concreteslab using a stencil (50 mm diameter, 10 mm thickness). After the mortarhas hardened, after 27 days, epoxy resin adhesive is used to adheremetal tensioning anchors to the mortar layer to be tested, in order tocarry out the tensile adhesion test.

The tensile adhesion values were tested in each case after a 14-daystorage period at 23° C. and 50% atmospheric humidity using a tensileapparatus from the company Herion with a rate of load increase of 250N/s. The measurement values in N/mm² are averages of 5 measurements.TABLE 2 WA WA WA WA WA WA WA TA Example 10′ 30′ 60′ 120′ 180′ 240′ 300′N/mm² 1 0.1 0.25 0.5 0.65 0.9 1.15 1.45 0.65 2 0.15 0.3 0.55 0.75 0.951.25 1.55 0.74 3 0.1 0.2 0.45 0.6 0.85 1.05 1.35 0.78 4 0.1 0.25 0.450.65 0.9 1.15 1.45 0.85 5 0.1 0.2 0.35 0.6 0.8 1.05 1.15 0.8 6 0.1 0.20.4 0.65 0.85 1.05 1.25 0.97 7 0.15 0.3 0.60 0.80 1.0 1.35 1.85 0.78 80.1 0.3 0.55 0.85 1.1 1.45 1.90 0.75 C1 0.2 0.45 0.65 1.05 1.25 1.652.05 0.73

Testing of a Joint Filler Formulation: Formulation 2 (joint filler):Portland cement CEM I 42.5 340.0 parts by weight Sand 649.5 parts byweight Cellulose ether 0.5 parts by weight Redispersible powder 10.0parts by weight Total 1000.0 parts by weight Water required 22.0 partsby weight

Determination of Water Absorption for Joint Fillers According to DIN EN12808:

A determination is made of the amount of water, in g, absorbed afterdefined periods of time on a mortar prism measuring 8×4×4 cm, which hasbeen given a watertight seal on the side faces and stored for 28 daysunder standard conditions prior to testing.

The higher the figure, the poorer the water repellency imparted to thespecimen.

The processing properties are determined on a qualitative basis by theperson carrying out the processing.

Testing of Flexural Strength Under Tension (FS):

To test the flexural strength under tension, in a method based on DIN18555, prisms measuring 16×4×4 cm were produced using the variousmortars and, before testing, were stored for 28 days under standardconditions.

Testing of Compressive Strength (CS):

To test the compressive strength, in a method based on DIN 18555, prismsmeasuring 16×4×4 cm were produced using the various mortars and, beforetesting, were stored for 28 days under standard conditions.

Testing of the Abrasion Resistance (AR):

The abrasion resistance is determined in accordance with EN 12808 or ENISO 10545-6. A rotating steel disc acts on the test specimen underdefined pressure and with application of abrasive. After 50 rotations ofthe steel disc the abrasion of the specimen is reported, in mm³. Thehigher the figure, the lower the abrasion resistance. TABLE 3 WA WA Pro-(30′) (360′) FS CS Hard- AR Ex. cessing [ml] [ml] [N/mm²] [N/mm²] ness(mm³) 1 good 1.41 2.92 2.75 8.39 good 1365 2 good 0.45 1.33 2.67 7.95good 1280 3 good 1.45 2.7 2.47 9.34 good 1260 4 good 0.38 1.28 2.61 7.78good 1195 5 good 1.24 2.81 2.96 10.39 good 1380 6 good 0.31 1.12 2.467.52 good 1232 7 good 1.50 3.1 2.53 7.45 good 1215 8 good 0.91 3.3 2.246.84 good 1556 C1 good 1.35 3.6 2.35 7.25 good 1450

DISSCUSSION OF THE RESULTS

From the data it is apparent that the skim coats and jointing materialsof the invention exhibit much lower water absorption values while havingat least equivalent or even improved mechanical values.

1-10. (canceled)
 11. A construction material comprising at least onehydraulically settable mineral binder, and a water repellent compositioncomprising an aqueous polymer dispersion or water-redispersible powder,said water repellent composition comprising a) a vinyl chloride-ethylenecopolymer comprising moieties derived from vinyl chloride in an amountof up to 95% by weight and 5% to 30% by weight of moieties derived fromethylene, b) 5% to 30% by weight of one or more protective colloids, c)and when in powder form, 5% to 30% by weight of one or moreanti-blocking agents, the amounts in % by weight being based on thetotal weight of the polymer powder composition and adding up in eachcase to 100% by weight based on components a), b), and c).
 12. Thematerial of claim 11, wherein at least one protective colloid b) isselected from the group consisting of partially hydrolyzed polyvinylalcohols having a degree of hydrolysis of 85 to 94 mol % and a Höpplerviscosity of 3 to 15 mPas in 4% strength aqueous solution (Höpplermethod at 20° C., DIN 53015), and partially or fully hydrolyzedcopolymers of vinyl acetate with isopropenyl acetate having a degree ofhydrolysis of 95 to 100 mol %.
 13. The material of claim 11, furthercomprising at least one additive selected from the group consisting ofd1) fatty acids and fatty acid derivatives which under alkalineconditions liberate fatty acid or the corresponding fatty acid anion,and d2) organosilicon compounds.
 14. The material of claim 12, furthercomprising at least one additive selected from the group consisting ofd1) fatty acids and fatty acid derivatives which under alkalineconditions liberate fatty acid or the corresponding fatty acid anion,and d2) organosilicon compounds.
 15. The material of claim 13, whereincomponent d1) comprises one or more fatty acid compounds selected fromthe group consisting of fatty acids having 8 to 22 carbon atoms; theirmetal soaps; their amides; and their esters with C₁₋₁₄ monohydricalcohols, with glycol, with polyglycol, with polyalkylene glycol, withglycerol, with mono-, di- or triethanolamine, and with monosaccharides.16. The material of claim 13, wherein component d2) comprises at leastone silicon compound selected from the group consisting of silicicesters, silanes, polysilanes, organosilanols and di-, oligo- andpolysiloxanes.
 17. The material of claim 11 which is a single-layercoating.
 18. The material of claim 11, which is a skim coat or amonocouche coating.
 19. The material of claim 11 which is a jointfiller.
 20. The material of claim 11, which comprises a in dry mortarformulation comprising 5% to 50% by weight of mineral binder, 5% to 80%by weight of filler, 0.1% to 10% by weight of polymer, and 0% to 30% byweight of further additives, the amounts in % by weight in theformulation adding up to 100% by weight.
 21. The material of claim 11,wherein the water repellant composition polymer is a water-redispersiblepowder.
 22. A process for the preparation of the construction materialof claim 11, comprising adding said water repellant composition to saidhydraulically settable mineral binder.
 23. A process for the preparationof the construction material of claim 12, comprising adding said waterrepellant composition to said hydraulically settable mineral binder. 24.A process for the preparation of the construction material of claim 13,comprising adding said water repellant composition to said hydraulicallysettable mineral binder.
 25. A process for the preparation of theconstruction material of claim 17, comprising adding said waterrepellant composition to said hydraulically settable mineral binder. 26.A process for the preparation of the construction material of claim 20,comprising adding said water repellant composition to said hydraulicallysettable mineral binder.
 27. The process of claim 26 further comprisingadding water and applying the construction material to a substrate andallowing to set.